Method of binding

ABSTRACT

A METHOD OF BINDING A QUANTITY OF SHEETS TOGETHER IN A STACK IN WHICH INDIVIDUAL SHEETS TO BE BOUND ARE ASSEMBLED IN OVERLYING STACKED RELATINSHIP WITH EACHSHEET HAVING ONE EDGE THEREOF UNIFORMLY POSITIONED ALONG A COMMON PLANE. A BEAD OF MOLTEN RESINOUS MEATERIAL IS THEN APPLIED TO THE EDGES OF THE SHEETS ALONG THE COMMON PLANE. THE BEAD OF RESINOUS MATERIAL IS THEN FLARED TO EXTEND FROM THE EDGES IN THE COMMON PLANE OVER PORTIONS OF THE UPPERMOST AND LOWERMOST SHEETS IN THE STACK. THE RESINOUS MATERIAL IS THEN SOLIDIFIED IN THE FLARED CONFIGURATION TO PROVIDE A BINDING FOR THE SHEETS ALONG THE UNIFORMLY POSITIONED EDGES.

cs. c. BHAGAT ET AL 3,707,418

METHOD OF BINDING Dec. 26, 1972 Filed Oct. 16. 1970 INVENTORY GOPAL C.BHAGAT BY JOSEPH 5: MAY

ATTORNEY United States Patent US. Cl. 156245 3 Claims ABSTRACT OF THEDISCLOSURE A method of binding a quantity of sheets together in a stackin which individual sheets to be bound are assembled in overlyingstacked relationship with each sheet having one edge thereof uniformlypositioned along a common plane. A bead of molten resinous material isthen applied to the edges of the sheets along the common plane. The beadof resinous material is then flared to extend from the edges in thecommon plane over portions of the uppermost and lowermost sheets in thestack. The resinous material is then solidified in the flaredconfiguration to provide a binding for the sheets along the uniformlypositioned edges.

BACKGROUND OF THE INVENTION This invention relates generally to sheetbinding and more particularly to a method for binding a quantity ofsheets together in a stack.

Numerous arrangements have heretofore been proposed for use in joiningor binding a plurality of sheets together in a stack. Perhaps the mostcommon method of sheet binding to date involves the use of a metallicU-shaped staple. Such staples are generally formed from drawn wire whichare driven under pressure through a stack of sheets and then bent orclinched on the bottom side of the stack. Various mechanicalarrangements have therefore been devised for forming the staples intothe characteristic U- shape as well as specific arrangements forinserting and tomoving the wire staples from a stack.

While the use of wire staples has generally proven satisfactory as ameans of joining or binding a plurality of sheets together in a stack,there have nevertheless been certain disadvantages associated with theuse of such binding or fastening arrangements. For example, the wirestaples often times have a tendency to buckle or bend during the processof being driven into the stack of sheets. Also, in many instances thewire staples are improperly bent or clinched on the under side of thestack. When either of these occur, the wire staple provides a less thaneffective means of binding together the sheets in the stack. When animproperly inserted staple is detected, the wasted staple must thereforebe removed and the process repeated until a properly driven and clinchedstaple is obtained. This results in unnecessary mutilation of the sheetsin the stack as well as consuming unnecessary operator time in thebinding operation.

In many instances, an improperly inserted staple may not be detected inthe binding operation. This is particularly true in the case of improperclinching on the under side of the stack. This results in a loosely heldstack of sheets which is susceptible to loss of sheets from the stack.In addition, such improperly clinched staples can also cause damage tounderlying stacks of sheets. Moreover, such improperly clinched staplespose the inherent possibility of effecting damage to clothing as well asinjury to a person handling such improperly bound stacks of sheets.

Another method of binding which has been utilized is that which has beencharacterized as adhesive binding. According to at least one method ofadhesive binding, sheets or signatures are collected and carried forwardin an upright position with the back or edges to be bound sup- 3,707,418Patented Dec. 26., 1972 ICC ported downwardly by means of clampsattached to a conveyor system. In the case of signatures, the foldedportions thereof may be cut off to leave all of the sheets separate inthe assembly. The edge of the back may then be coated with an adhesivematerial and spread to a uniform thickness thereon by suitable means,such as a roller applicator member for example. A permeable flexiblebacking may then applied to the adhesive material and a subsequentcoating of adhesive material applied thereto to complete the bindingarrangement after drying of the adhesive material has taken place.

Another form of adhesive binding involves the use of special tapeshaving adhesive materials coated thereon. The adhesive material on suchtapes is usually normally in a non adhesive state and is activated to anadhesive state just prior to application through the use of heat orsolvents. When applied to the back of a group of sheets these adhesivecoated tapes provide the binding mechanism by which sheets are heldtogether.

While previous binding arrangements have found application in variousbinding operations, there nevertheless has existed a need for animproved, more effective and more efiicient method for binding sheetstogether in a stack.

SUMMARY OF THE INVENTION Accordingly, it is an objective of the presentinvention to provide an improved method of binding a quantity of sheetstogether in a stack.

It is another object of the present invention to provide an economicaland effective method of binding a quantity of sheets together in astack.

It is still another object of the present invention to provide a novelmethod of binding a quantity of sheets together in a stack whichexhibits excellent holding capability.

It is a further object of the present invention to provide a method ofbinding a quantity of sheets together in a stack which results in anattractive fastening arrangement.

It is yet a further object of the present invention to provide a novelmethod of binding a quantity of sheets together in a stack which iseffective and reliable in maintaining the integrity of the boundmaterial.

These and other objects of the present invention are attained byassembling the individual sheets to be bound in overlying stackedrelationship with each sheet having one edge thereof uniformlypositioned along a common plane, applying a bead of molten resinousmaterial to the edges of the sheets along the common plane, flaring thebead of resinous material from the edges to extend over portions of theuppermost and lowermost sheets in the stack and solidifying the resinousmaterial in the flared configuration.

Other objects of the invention will become readily apparent to thoseskilled in the art in view of the following detailed disclosure anddescription thereof, especially when read in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an end view showing anassembled stack of sheets which are to be bound together.

FIG. 2 is an end view showing an assembled stack of sheets with a beadof resinous material applied to the edges of the sheets in the stack.

FIG. 3 is an end view showing the stack and bead of FIG. 2 beinginserted into a mold.

FIG. 4 is an end view showing the stack and head of FIG. 2 with the diesof the mold of FIG. 3 closed.

FIG. 5 is an end view showing an alternate configuration of the moldingdies of FIGS. 3 and 4.

FIG. 6 is an end view showing a finished bound stack of sheets accordingto the arrangement of FIGS. 1-4.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1-4 of thedrawings,there are illustrated various steps in the method of binding ascontemplated by the present invention. As illustrated therein, aquantity of sheets 10 which are to be bound together are assembled inoverlying stacked relationship. In the stacked relationship one edge ofeach of the individual sheets 10 is uniformly positioned along a commonplane such as the plane of the stack as seen at the bottom of FIG. 1.Various known sheet handling apparatus may be employed to produce thisrelationship such as sheet stackers, sheet joggers or other similartypes of sheet handling devices.

With the individual sheets 10 thus assembledand positioned, a bead ofmolten resinous material is applied to the edges of the sheets 10 alongthe common plane or spine While any suitable material may be utilized inthe binding method as contemplated by the present invention, a resinousmaterial is preferred. Although the specific material chosen may varywith the particular application, the material according to a preferredembodiment should generally exhibit the characteristic of being moltenor flowable and of solidifying when used in accordance with the presentinvention. Typical materials include thermoplastic and thermosettingresins, metals and rubber. Typical thermoplastic materials includepolymers and copolymers of polyolefins such as polyethylene,polypropylene, chlorinated polyethylene, chlorosulfonated polyethylene;polymers and copolymers of vinyl and vinylidenes such as polystyrene,polymethylstyrene; acrylic polymers such as polymethyl methacrylate,polyacrylic acid, polyacrylonitrile; polyvinyl esters such as polyvinylacetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride,polyvinyl carbazole, polyvinyl ethers, polyvinyl ketones; polymers andcopolymers of fluorocarbons such as polytetrafluoroethylene, polyvinylfluoride, polyvinylidenefluoride, polychlorotrifluoroethylene; andpolymers and copolymers of heterochain thermoplastics includingpolyamides such as polycoproloctamo, polyhexamethylene adipamide;polyesters such as polyethylene terephthalate, polyurethanes;polypeptides such as casein, zein; ether and aeetal polymers such aspolyoxymethylene, polyglycol, polysulfides, polycarbonates; cellulosicpolymers such as viscose, cellophane, cellulose acetate. Typicalthermosetting resins include polymers and copolymers of phenolic resinssuch as phenol-formaldehyde, phenol-furfural, resorcinol formaldehyde;polymers and copolymers of amino resins such as urea-formaldehyde,melamine-formaldehyde; polymers and copolymers of polyester resins;polymers and copolymers of epoxy resins; polymers and copolymers ofurethanes; polymers and copolymers of silicone resins; and polymers andcopolymers of miscellaneous resins including alkyd resins, alkyl resins,and furan resins.

The bead of molten material may be applied to edges of the sheets in thestack by any suitable means. Various known arrangements by which themolten material may be applied include dipping the edges of the sheetsin a reservoir containing the molten material as well as applicatormethods employing rollers, wheels, brushes and sprays. The moltenmaterial when applied to the edges of the sheets adheres thereto bywetting the edges of the sheets and according to the preferredarrangement should be applied in suflicient quantities to form a largebead 15 as shown in FIG. 2.

After the head 15 of molten resinous material has been applied to theedges of sheets 10 along the spine or common plane, the bead 15 ofmolten material is flared from the edges in the common plane overportions of the uppermost and lowermost sheets in the stack. This may beac- 4. complished in a variety of ways. However, flaring by the use ofmolding dies is preferred.

One arrangement by which the bead of molten material may be flared fromthe edges of the stack in the common plane over portions of theuppermost and lowermost sheets in the'stack is by the use of a diearrangement such as that shown in FIGS. 3 and 4. As illustrated therein,dies 11 and 12 having respectively associated-molding surfaces 13 and 14are mounted in opposed relationship for reciprocal movement on'basemember 16. According to this arrangement, a portion of the surface ofbasemember 16 over which die members 11 and 12 are reciprocably movablealso serves as a portion of the total molding surface for the flaringoperation.

According to a preferred arrangement, die members 11 and 12 areresiliently biased by spring members or other suitable biasing means ina direction toward each other on base member 16. Thus, a stack of sheets10 with bead 15 of molten material applied theretomay be inserted intothe die arrangement of FIGS. 3 and :4 'with'die members 11 and 12engaging the uppermost and lowermost sheets of the stack respectively.Suitable means may also be provided for effecting movement of one'orboth of the die members Hand 12 against the action of the respectivelyassociated spring members to a position such as shown in FIG. 3 prior toinsertion of the stack thereby permitting ready insertion of the stack10 into the molding arrangement for the flaring operation. I

With the stack 10 inserted between dies 11 and. 12 over base member 16,the dies 11 and 12 are allowed to be moved under the influence of therespectively associated spring members to contact the respectiveuppermost and lowermost sheets in the stack. In this position as may beseen in FIG. 4, portions of the head 15 are forcedoutwardly and upwardlyover the uppermost and lowermost sheets in the stack. It will beappreciated that during the flaring operation, the stack of sheets 10 isspaced a predetermined distance from base member 16 so as to provide afinite thickness of material along the edges of the sheets 10. It willalso be appreciated that as a result of the configuration of the moldingsurfaces 13 and 14 a finite thickness of the flared material is alsoprovided along the uppermost and lowermost sheets in the stack. Thecombined action therefore, of molding surfaces 13 and 14 in conjunctionwith a portion of the surface of base member 16 serve to flare bead 15from the edges of the sheets 10 as seen in FIG. 2 to extend in apredetermined thickness around the spine or common plane and overportions of the uppermost and lowermost sheets in the stack'as seen inFIG. 4.

With the stack of sheets 10 supported between molding surfaces 13 and 14and over base member 16, the stack may be transported along the lengththereof through the die members by any suitable conveying or supportingarrangement. As the stack 10 is thus transported, bead 15 will be flaredoutwardly and upwardly from the common plane or spine of the stack overthe uppermost and lowermost sheets in the stack along the length of thestack 10.

After the flaring or molding operation, has been completed, the moltenmaterial is solidified in the flared configuration. For most materialsthis is accomplished as the material is cooled from an elevatedtemperature to normal ambient room temperature. For other materials thismay be accomplished by evaporation of plasticiiers or solvents from themolten material in the flared configuration.

As may be seen from FIG. 6 the binding arrangement when performedaccording to the described method yields a stack of sheets 10 which areheld together by means of the solidified resinous material. The resinousmaterial in the flared configuration adheres to the edges of theindividual sheets along the spine or common plane and in the generallyU-shaped configuration of predetermined thickness, engages both theuppermost and lowermost sheets in the stack to provide an efiective,reliable, and

attractive binder for supporting the sheets in a stack or book.

It should be appreciated that the resinous material may be flared intovarious configurations other than the configuration illustrated in FIGS.1-4 and 6, for example, the configuration shown in FIG. 5. In theconfiguration of FIG. 5 a greater quantity of resinous material isretained along the edge portion of the stack to reinforce the resultingbinding arrangement along the edges of the \sheets. Other configurationsmay equally provide an effective and reliable binding arrangement. Itshould also be appreciated that the flaring operation may beaccomplished by means other than the molding arrangement specificallydescribed in connection with FIGS. l-4 and that means many be associatedwith the die members for scraping or removing excess amounts of theresinous material.

From the foregoing arrangement it will therefore be appreciated that thebinding method as contemplated by the present invention may beimplemented in a variety of embodiments which provide economical,effective and reliable means for binding a quantity of sheets togetherin a stack.

While the binding method as contemplated by the present invention hasbeen described with reference to preferred arrangements, it will begenerally understood by those skilled in the art that various changesmay be made and equivalents may be substituted for elements thereofwithout departing from the true spirit and scope of the invention.

What is claimed is: 1. A method of binding a plurality of sheetstogether in a stack comprising,

assembling individual sheets in overlying stacked relationship with eachsheet having one edge thereof uniformly positioned along a common plane,

applying a bead of molten resinous material to the edges of said sheetsalong said common plane,

subjecting said uniformly positioned edges and said applied bead ofresinous material to the internal molding surfaces of a die member toflare portions of said resinous material from said edges over portionsof the uppermost and lowermost sheets in said stack, and

solidifying said resinous material in said flared configuration to forma binding for said sheets along said uniformly positioned edges.

2. A method of binding a quantity of sheets together in a stackcomprising,

assembling individual sheets in overlying stacked relationship with eachsheet having one edge thereof uniformly positioned along a common plane,

applying a bead of molten resinous material to the edges of said sheetsalong said common plane,

flaring portions of said bead of resinous material from said edges overportions of the uppermost and lowermost sheets in said stack bysubjecting said bead to the internal molding surfaces of a die member,and

solidifying said resinous material in said flared configuration to forma binding for said sheets along said uniformly positioned edges.

3. A method of binding a quantity of sheets together to form a bookcomprising,

assembling the individual sheets in overlying stacked relationship witheach sheet having one edge thereof uniformly positioned along a commonplane,

applying a bead of molten resinous material to the edges of said sheetsalong said common plane,

subjecting said uniformly positioned edges and said applied bead ofresinous material to a die having a molding surface of a predeterminedconfiguration to produce a flow of said resinous material within saiddie over a portion of the surfaces of the uppermost and lowermost sheetsin said stack adjacent the uniformly positioned edges, and

solidifying said resinous material in a configuration conforming to saiddie to form a binding for said sheets along said uniformly positionededges.

References Cited UNITED STATES PATENTS 2,558,405 6/ 1951 Weinstein 28222R 2,922,417 1/1960 Bradley et al 156245 X FOREIGN PATENTS 902,209 8/1962 Great Britain l56295 RICHARD D. LOVERING, Primary Examiner US. Cl.X.R.

156292, 295, 305; 16l149, 268; 2828 R, 22 R, DIG. 2

